JPS62266483A - Semiconductor radiation detector array - Google Patents

Abstract

PURPOSE:To enable highly accurate measurement, by performing an arithmetic processing based on the number of output pulse signals issued from an array for detecting scattered rays and the number of output pulse signals for detecting direct rays to remove effects of scattered rays. CONSTITUTION:A semiconductor radiation detector array 1 for detecting direct rays and a semiconductor radiation detector array 2 for detecting scattered rays are arranged and fixed on a stationary metal plate 3 in parallel at an interval of about 0.5mm so that unit detection elements of these detectors will be adjacent to one another to form a semiconductor radiation array. Here, the interval between the arrays 1 and 2 is preferably less than 3mm. The size of the unit detection elements is desired to be the same. The semiconductor radiation detector thus obtained is so set on an X-ray diagnosing apparatus that an X-ray fan beam 6 will irradiate the array 1 alone and an object 7 to be inspected is arranged in the direction of admitting X rays. Then, an arithmetic processing is performed by a specified formula based on the number of pulses outputted from a unit detection element section of the array 1 and the number of pulses outputted from a unit detection element section of the array 2 adjacent thereto to remove effects of scattered rays incident into the array 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a semiconductor radiation detector array used in a medical X-ray diagnostic apparatus.

(Prior Art) A semiconductor radiation detector array is an arrangement of a plurality of semiconductor radiation detectors that are sensitive to radiation, and is used as a detector for an X-ray diagnostic device.

As shown in FIG. 3, the configuration was such that a subject 13 was placed between an X-ray fan beam 11 and a semiconductor radiation detector array 12, and X-rays 14 transmitted through the subject 13 were detected.

In the above configuration, the X-ray fan beam 11
Since the scattered rays 15 generated when passing through the semiconductor radiation detector array 12 also enter the semiconductor radiation detector array 12, the output signal is affected by the scattered rays.

In recent years, medical X-ray diagnostic equipment has been required to perform measurements with even higher precision, and it has become necessary to detect minute differences in absorption coefficients within a subject.

(Problems to be Solved by the Invention) The conventional configuration described above has the disadvantage that highly accurate measurement is difficult because the influence of scattered radiation is added to the output signal.

An object of the present invention is to eliminate the conventional drawbacks by calculating the number of output pulse signals from a scattered ray detection array into the number of output pulse signals for direct ray detection.

An object of the present invention is to provide a semiconductor radiation detector array that can eliminate the influence of scattered radiation.

(Means for Solving the Problems) The semiconductor radiation detector array of the present invention is a semiconductor radiation detector array in which a plurality of semiconductor radiation detectors sensitive to radiation are arranged. The array is arranged parallel to the radiation incident cross section, one of which is used for direct ray detection and the other for scattered ray detection.

In addition, it is a semiconductor radiation detector array in which a plurality of semiconductor radiation detectors sensitive to radiation are arranged, in which three semiconductor radiation detector arrays are arranged parallel to the radiation incident cross section, and one in the center is used for direct detection. , and others are used for detecting scattered radiation.

Further, the distance between the direct ray detection array and the scattered ray detection array is 3 m+s or less.

Furthermore, the unit detection element portions of the direct radiation detection array and the scattered radiation detection array are arranged adjacent to each other.

In addition, the unit detection elements of the direct radiation detection array and the scattered radiation detection array have the same volume, and furthermore, when used in a detector for an X-ray diagnostic device, XA! The fan beam is adjusted so that it is irradiated only on the direct ray detection array, and the number of pulses output from each unit detection element section of the direct ray detection array is adjusted to the number of pulses output from the unit detection element section of the adjacent scattered ray detection array. By performing arithmetic processing using the number of output pulses, the influence of scattered radiation incident on the direct radiation detection array is removed.

(Function) The function of the technical means of the present invention is as follows. By calculating the number of output pulse signals from the scattered ray detection array into the number of output pulse signals for direct ray detection, the influence of scattered rays can be removed.

(Example) An example of the present invention will be described based on FIGS. 1 and 2.

FIG. 1(a) is a perspective view of a semiconductor radiation detector array of the present invention, and FIG. 1(b) is a diagram of the same principle.

In the figure, 1 is a semiconductor radiation detector array for direct ray detection (hereinafter abbreviated as direct ray detection array), 2 is a semiconductor radiation detector array for scattered ray detection (hereinafter abbreviated as scattered ray detection array), and 3 is A metal fixing plate for fixing the array, 4 is a signal extraction lead from each unit detection element of the array, 5 is a common lead, 6 is an X-ray fan beam, 7 is a subject,
8 is a transmitted X-ray, and 9 is a scattered ray.

As shown in FIG. 1(a), a direct line detection array 1 and a scattering detection array 2 are arranged in parallel on a metal fixing plate 3 at an interval of 0.5+am so that each unit detection element is adjacent to the other. The semiconductor radiation detector array is constituted by two semiconductor radiation detector arrays. Here, the distance between direct ray detection array 1 and scattered ray detection array 2 is 3a+m
This semiconductor radiation detector is preferably Installed in the line diagnostic equipment, Fig. 1(b)
The subject 7 is placed in the xi incident direction as shown in FIG. Transmitted X-rays 8 transmitted by the X-ray fan beam 6 through the object 7 are incident on each unit detection element of the direct ray detection array 1, and scattered rays 9 from the object 7 are incident thereon. An output pulse signal is generated by adding the number of photons in the line.

Here, the number of pulse signals output by each unit detection element of the direct line detection array 1 is assumed to be nl.

On the other hand, only the scattered radiation 9 from the subject 7 enters each unit detection element of the scattered radiation detection array 2 . Here, the number of pulse signals output by each unit detection element of the scattered radiation detection array 2 is assumed to be n2.

Next, the calculation shown in the following equation is performed.

n = nt k n2・----(DHere, k is a constant and is determined by measurement conditions such as the size of the unit detection element and the distance between the direct ray detection array 1 and the scattered ray detection array 2. is determined so that kn2 is the same as the number of output pulses due to the scattered radiation 9 incident on the unit detection element portion of the direct radiation detection array 1.

n calculated by the calculation of formula (1) is the number of photons incident on each unit detection element part of the direct detection array 1 by removing the number of photons due to scattering @ 9, and the number of photons that directly pass through the object 7. This is the number of photons, and it becomes possible to measure only the direct line from the subject.

In this example, a direct ray detection array 1 and a scattered ray detection array 2 were prepared, but one semiconductor radiation detector array was divided into two in the axial direction, one for direct ray detection and the other for scattering. It may also be used for line detection.

FIG. 2 shows another embodiment of the present invention, in which a direct line detection array 1 is shown.
It has a configuration in which two scattered radiation detection arrays 2 are arranged in parallel on both sides. As in the embodiment of FIG. 1(a), it is preferable that the unit detection elements of each array are adjacent to each other with a small interval from the unit detection elements of other arrays.

In this embodiment, the number of pulses output from each unit detection element of the direct radiation detection array 1 is n□1, and the number of pulses output from one adjacent unit detection element of the scattered radiation detection array 2 on both sides is n2. , the number of pulses output from the other unit detection element is n, then the number of output pulses due to the X-rays that have passed through the subject is determined by equation (2), which is similar to equation (1).

n=n1−k(nz+n,)−・−・(2)k is the same as the embodiment shown in FIG. n2+
This is a constant determined to be equal to n□).

In this embodiment, similarly to the above embodiment, one semiconductor radiation detector array may be divided into three parts in the axial direction, with the center being used for direct radiation detection and the both sides being used for scattered radiation detection.

(Effect of the invention) According to the invention, when the X-rays pass through the subject.

It can eliminate the influence of the scattered radiation that occurs, making it possible to perform highly accurate measurements, which has a great practical effect.

[Brief explanation of drawings]

FIG. 1(a) is a perspective view of a semiconductor radiation detector array according to an embodiment of the present invention, FIG. 1(b) is a diagram of the same principle, and FIG. 2 is a semiconductor radiation detector according to another embodiment of the present invention. The array perspective view and FIG. 3 are cross-sectional views showing the principle of a conventional semiconductor radiation detector array. 1... Semiconductor radiation detector array for direct line detection, 2
...Semiconductor radiation detector array for detecting scattered radiation, 3.
・・Metal fixing plate, 4 ・・Signal extraction lead, 5
... Common lead, 6 ... X-ray fan beam, 7 ... Subject, 8 ... Transmitted X-ray, 9 ...
Scattered rays. Patent applicant: Matsushita Electric Industrial Co., Ltd. Figure 1 Figure 2

Claims (6)

[Claims] (1) A semiconductor radiation detector array in which a plurality of semiconductor radiation detectors sensitive to radiation are arranged, wherein the plurality of semiconductor radiation detector arrays are arranged parallel to a radiation incident cross section, and one of the semiconductor radiation detector arrays is arranged in parallel to a radiation incident cross section. A semiconductor radiation detector array characterized in that one is used for direct radiation detection and the other is used for scattered radiation detection. (2) A semiconductor radiation detector array in which a plurality of semiconductor radiation detectors sensitive to radiation are arranged, in which three semiconductor radiation detector arrays are arranged in parallel to a radiation incident cross section,
The semiconductor radiation detector array according to claim 1, wherein one of the central detectors is used for direct detection and the other detectors are used for scattered radiation detection. (3) The semiconductor radiation detector array according to claim (1) or (2), wherein the distance between the direct radiation detection array and the scattered radiation detection array is 3 mm or less. (4) Any one of claims (1) to (3), characterized in that the unit detection element portions of the direct radiation detection array and the scattered radiation detection array are arranged adjacent to each other. The semiconductor radiation detector array according to item 1. (5) The unit detection elements of the direct radiation detection array and the scattered radiation detection array have the same volume, according to any one of claims (1) to (4). Semiconductor radiation detector array. (6) When used in a detector for an X-ray diagnostic device, the X-ray fan beam is adjusted so that it is irradiated only to the direct detection array, and is output from each unit detection element section of the direct detection array. The effect of the scattered radiation incident on the direct radiation detection array is removed by calculating the number of pulses using the number of pulses output from the unit detection element section of the adjacent scattered radiation detection array. Claim No. 1
) to (3).